1. Technical Field
The invention relates to network traffic management in a computer environment. More particularly, the invention relates to traffic scheduling between multiple independent content delivery networks in a computer environment.
2. Description of the Prior Art
A Content Delivery Network (CDN) is collection of caching, streaming, storage, and other servers distributed throughout the Internet in order to deliver content closer to the end user, avoiding the “middle mile” problem.
CDN's provide two main benefits to their users (in this case the user is the customer or content owner, not the end user). The first is reduction of traffic at the origin site. Every request that arrives at the CDN is a request not arriving at the origin site. This means that the origin site will have less work to do as it utilizes the CDN more and more. In addition, the type of work that is being removed is often very different than what will continue to be directed at the origin site. As an example, all of the requests for images which result in many connections to a server are removed from the origin while connections that need access to the database remain. This allows the origin site to be tuned for the database type requests that it will be receiving. A CDN of at least one POP will provided this benefit to a customer.
The second benefit is increased performance for the delivery of the content by reducing the network delay between the browser and the content. This is done by placing servers in locations near the end users and using a system to direct end users to the “best” server. Each customer will have a different group of end users. Some will need full global coverage while other may only need certain parts of the world.
A network provider building their own CDN has a very cost effective solution for solving the first problem of reducing origin site load. Owning their own network, they often see their internal costs for using it as very low, and as a result can price a CDN solution very low. The ability of a given network provider to solve the second issue with only their own connectivity, will not work for all customers.
Today there are two types of CDNs generally available: facilities-based CDNs (also referred to as an on-net CDN) and multi-network CDNs. A facilities-based CDN has deployment limited to a single service provider's network and points of presence (POPs). A multi-network, CDN has servers distributed on many different service provider networks and POPs.
In general, multi-network CDNs provide higher performance, availability, redundancy, and scalability than facilities-based CDNs, due to the fact that no one service provider network controls all the content providers (servers) and/or the eyeballs (clients). Also, not many service providers have sufficient coverage and POPs to distribute and deliver content. Thus, a multi-network CDN will outperform a facilities-based CDN in all cases.
However, some service providers still want to create a facilities-based CDN in order to maintain traffic on their own network as well as to participate in this new and growing market. There is a need to provide the facilities-based CDN providers the advantages of multi-network CDNs.
It would be advantageous to provide a meta content delivery network system that provides load balancing and traffic scheduling across independent CDNs in a computer network. It would further be advantageous to provide a meta content delivery network system that allows CDN providers to designate the availability of their networks.